Interfacial dynamics following photoexcitation of a water oxidation assembly on nanocrystalline TiO2 electrodes have been investigated. Transient absorption measurements reveal that electron injection occurs with high efficiency but that hole transfer to the catalyst, which occurs on the electrochemical time scale, is inhibited by local environmental effects. These results and analyses show that the transient surface behavior of the assembly and cross-surface reactions play important roles in producing and storing redox equivalents on the surface that are used for water oxidation.

Brennaman, M. K.; Gish, M. K.; Alibabaei, L.; Norris, M. R.; Binstead, R. A.; Nayak, A.; Lapides, A. M.; Song, W.; Brown, R. J.; Concepcion, J. J.; Templeton, J. L.; Papanikolas, J. M.; Meyer, T. J. Pathways following Electron Injection: Medium Effects and Cross-Surface Electron Transfer in a Ruthenium-Based, Chromophore-Catalyst Assembly on TiO2. J. Phys. Chem. C 2018, 122 (24), 13017-13026. http://dx.doi.org/10.1021/acs.jpcc.8b04837